Background: While it is assumed that dialysis patients in Japan have a higher prevalence of atrial fibrillation (AF) than the general population, the magnitude of this difference is not known.Methods: Standardized prevalence ratios (SPRs) for AF in dialysis patients (n = 1510) were calculated compared to data from the general population (n = 26 454) living in the same area.Results: The prevalences of AF were 3.8% and 1.6% in dialysis patients and the general population, respectively. In male subjects, these respective values were 4.9% and 3.3%, and in female subjects they were 1.6% and 0.6%. The SPRs for AF were 2.53 (95% confidence interval [CI], 1.88–3.19) in all dialysis patients, 1.80 (95% CI, 1.30–2.29) in male dialysis patients, and 2.13 (95% CI, 0.66–3.61) in female dialysis patients.Conclusions: The prevalence of AF in dialysis patients was twice that in the population-based controls. Since AF strongly contributes to a higher risk of cardiovascular mortality and morbidity in the general population, further longitudinal studies should be conducted regarding the risk of several outcomes attributable to AF among Japanese dialysis patients.